Device for shaping gold crowns to teeth.



J. 0. SCHWARTZ.

bB v IcE FOR SHAPINE; GOLD oRowns T0 TEETH.

APPLICA'BION FILED P13851912 Patented Feb. 11, 1913.

2 SHEETS-SHEET l.

- J. Q. SCHWARTZ. DEVICE FOR SHAPING GOLD CRUWNS TO TEETH.

APYLICATION FILED FEB 5, 1912 1,052,850. Patented Feb. 11,1913.

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JACOB C. SCHWARTZ, OF ST. LOUIS, MISSOURI.

DEVICE FOR SHAPING GOLD CROWNS TO TEETH.

Specification of Letters Patent.

Patented Feb. 11,1913.

Application filed February 5, 1912. Serial No. 675.543.

To all whom it may concern:

Be it known that I, Jacon C. SCHWARTZ, av citizen of the United States,residing at the city of St. Louis and State of Missouri, have inventedcertain new and useful Improvements in Devices for Shaping Gold Crownsto Teeth, of which the following is a specification.

This invention relates to dental apparatus and pertains particularly todevices for pressing metal crowns into the sha e of teeth, the objectbeing to provide a (evice of this character in which the malleablemetal, such as lead, or the like, that is used for pressing the crownaround the model of the tooth, is molded in one piece instead of severalpieces as has been heretofore customary.

Further, the present invention contemplates the provision of a device,in which not only the malleable metal can be molded in a single )iece,but, also, in which the malleable nieta l can be compressed to press thecrown around the model of the tooth.

In the accompanying drawings forming art of this specification, in whichlike numiiors of reference denote like parts wherever they occur, Figurel is a perspective view of the device; Fig. 2 is a sectional view on theline 22, Fig. 1; Fig. 3 is a. side elevation of the member for dividingthe interior of the mold into two compartments; Fig. 4 is a perspectiveview of the piece of ma leablc metal removed from the mold; Fig. 5 is anelevation, on an enlarged scale, of the model of a tooth; Fig. 6 is aperspective view, on an enlarged scale, of the metal cap or thimblebefore same is formed into the shape of the tooth; Fig. 7 is anelevation, on an enlarged scale, showing the metal cap or thimblo uponthe model of the tooth after the tooth indentations have been formed inthe closed end of the former; Fig. 8 is an elevation, on an enlargedscale, showing the metal cap or thimble upon the model of the toothafter the wall of the former has been pressed snugly against. the sidesof the tooth model; Fig. 9 is a perspective view of the completed orfinished crown; Fig. 10 is a vertical sectional view of the mold inconjunction with the device for compressing the malleable metal aroundthe cap or thimble upon the tooth model; and Fig. 11 is a verticalsectional view of the mold showing a device in conjunction therewith forreducing the opening in the malleable inetah The device consists of amold 1 which is preferably formed of a cylindrical piece of steel orother suitable metal having either part or all of its periphery milledto form a roughened grasping surface and containing a relatively deepdepression 2 in its upper end. The upper part of the depression 2 ispreferably cylindrical, and the lower part of the same tapers inwardlytoward the bottom thereof where said depression is rounded, as depictedin Fig. 2. Said depression 2 is divided vertically into two compartments3 by means of a blade 4 which is secured in a slot 5 in the lower end ofa mandrel 6 by a pin 7 or other suitable means. The upper end of themandrel 6 extends above the top of the blade 4, in order to atl'ord ahandle by which the same is held when the blade is inserted into orremoved from the depression 2 in the mold 1, and the lower end of saidmandrel termimites within a shortdistance of the lower ed e of saidplate, the slot 5 being preferably arranged to extend longitudinallythrough the axis of said mandrel, so that the two parts of the latterthat embrace the blade 4 serve the purpose of a core, as hereinafterdescribed, and said mandrel being preferably located centrally of saidblade, so that when the latter is inserted into its proper position inthe mold, the axis of the inaudre will coincide substantially with theaxis of the depression 2. The blade 4 bears a pair of cars orproject-ions 8, the latter be ing arranged to project from the oppositeedges of said blade and being adapted to seat in a )air of grooves 9formed in the upper sur ace of the mold, said grooves being disposeddiametrically opposite each other, with respect to the axis of thedepression 2. The blade 4 is formed with a configuration that issubstantially the same as the vertical sectional configuration of thedepres sion 2,so that, when the blade isinserted into its properposition in the mold, i. 0., with its ears 8 resting in the grooves 9,the Side. and lower edges of the blade 4 fit closely to the sides andbottom of the depression 2, whereby the two compartments 3 into whichthe depression is divided by said blade are separated from each otherwithout any com munication except through a notch 10 in the lower edgeof said blade, said notch being preferably located below the lower endof the mandrel 6.

After the blade 4 is inserted into its lli proper position in the mold 1so that the ears 8 of the fo rmer rest in the grooves 9 in the latter,as shown in Fi 1, a low fusing malleable metal, prefera bly lead, in amolten state'is oured into one of the compartments 3 of t 1e depression2. The molten lead not only fills the compartment 3 into which it ispoured, but, also, at the same time, runs throu h the notch 10 in thelower edge of blade 4 into the other compartment 3, thereby filling bothcompartments to substantiall the same level. \Vhcn the lend has coo edin the mold, the blade 4 and mandrel (S are removed from the mold bygrasping the upper end of said mandrel and mlhng the same upwardly, thusleaving the lead in the mold. The blade 4 forms a slot 11 between thetwo halves 12 of the lead within the mold, and the two parts of themandrel 6 that embrace the blade 4 form do )ressions in the opposingfaces of the two halves 12 of the lead, which depressions register witheach other and form a central openin 13, said halves 12 being connectedat the bottom by the lead that cools in the notch 10 in said blade, asclearly illustrated in Figs. 10 and 11.

An impression of the broken tooth to be crowned is taken, and, from suchimpression, a metal model 14 of the whole tooth is made in the usualmanner with a groove 15 formed therein to define the gum line betweenthe tooth proper and the root portion, said model being preferabl formedof a com osition of tin, lead, ant bismuth. The mo el 14 is used as a.die to form an impression of its crown in a piece of lead or othersuitable metal (not shown) and then, with the proper size of metal capor thimble 16, preferably of gold, fitted upon the tooth portion of themodel 14 said cap is driven into the im )ression in the piece of lead bymeans of the model 14, so as to form the same indentations in the closedend of the cap as are in the crown of the model 14, as illustrated inFig. 7. The model 14 with the indented ca 16 upon the tooth portion ofthe same is then placed into the openin" 13 in the lead in the mold 1with the mode inverted, so that said cap rests upon the. bottom of saidopening, as shown in Fi 10. A block 17 of steel or other suitab e metal,preferably cylindrical in sha e and having a shank 18, which is adaptedto fit in the upper part of the depression 2, is placed so that saidshank rests upon the tops of each half 12 of the lead within the mold 1,and then the to of said block is hammered, so as to drive t e shank 18downwardly into the depression 2, thereby compressing the two halves 12of the lead around the cap 16, so as to press the latter closely aroundthe model 14. By this means, the cap 16 is pressed into the same sha eas the tooth portion of the model 14 an the metal of said cap adjacentthe roove 15 in the model is pressed into saitl groove, in order to formthe gum line on said ca as shown in Fig. 8. After the cap 16 has beenpressed closely around the model 14 as just described, the lead isremoved from the mold and is then cut or removed in any other suit--able manner-from around said model and cap. The model 14 is then melted,so as to run out of the cap 16, after which the part of the latter belowthe um line is cut away, so as to leave the hoilow gold crown 16" withthe same shape as the tooth, as depicted in Fig. 5). The finished crown16" is then ready to be cemented in the usual manner u on the brokentooth to be crowned. In OH or to prevent the lower edge of the shank 18of the block 17 from chipping the edge of the depression 2 in mold 1, abevel 19, preferably somewhat concave, is formed on t ie ed e of saiddepression, so as to cause the shant 18 to slide into the depressionwithout chipping the edge of said depression in case the edge of saidshank strikes said bevel.

It should be understood that blades having different sizes or mandrels 6secured thereto as hereinabove described or formed integrally therewithmay be used, so as to form the proper size openings 13 in the lead inthe mold for the various sizes of ca s 16. In case, however, it isdesired to recuce the size of the opening 13 in the lead in the mold 1,a block 20 of steel or other suitable metal, preferably cylindrical inshape and having a shank 21, which is adapted to fit in the upper partof the depression 2 is placed so that said shank 21 rests upon the topsof each half 12 of the lead within the mold 1. Said block 20 contains ano ening 22, which extends longitudinally tirough the middle of the same,in order to register with the opening 13 in the lead in the mold. Amandrel 23 of the proper size to which the opening 13 is to 0 reduced isinserted into the opening 13, so that the lower end of same rests u onthe bottom of said opening, said mandre 28 being preferabl of suchlength that the upper end thereo pro'ects into the lower part of theopening 22 1a block 20, as depicted in Fig. 11. The top of the block 20is then hammered, so as to drive the shank 21 downwardly into the deression 2, whereby the two halves 12 of tie lead are compressed 2against the mandrel 23 and the opening 13 consequeutlfy reduced to thesize of said mandrel, a ter which the block 20 and mandrel 28 areremoved.

I claim:

1. A piece of lead or similar metal for pressing a crown around themodel of a tooth and molded in two 0 posing halves united integrally atone ent, the opposing faces of said halves having depressions 1'therein, the depressions in said halves uniting to form an opening forthe reception'of the tooth model with a crown fitted thereon.

2. A piece of lead or similar metal for pressing a crown around themodel of a tooth and molded in two 0 posing halves nnited integrally atone on the opposing faces of said halves having depressions therein, thedepressions in said halves nniting to form an opening for the receptionof the tooth model with a crown fitted thereon, one end of said openingbeing closed by the lead that unites said halves.

.3. A piece of lead or similar metal molded in two 0 posing halves forressing a crown around the model of a toot i received between saidhalves, the latter being united integrally at one end thereof.

4. A one-piece malleable metal member for pressing a crown around themodel of a tooth, formed of a plurality of sections integrally connectedat one end, the confronting faces of the sections being recessed toconjointly form an opening for the reception of the tooth model with acrown fitted thereon.

5. A one-piece malleable metal member for pressing a crown around themodel of a tooth, formed of a plurality of sections integrally connectedat one end, the confronting faces of the sections being recessed toconjointly form an opening for the reception of the tooth model with acrown fitted thereon, one end of said opening being closed by saidintegral connection between the sections.

In testimony whereof I hereunto affix my signature in the presence oftwo witnesses.

JACOB C. SCHWARTZ.

\Vitnesses:

Ma'rrls C. GUELS, Bnn'rna VON BEHRENS.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. C.

